Aussie fashion royalty Heidi Middleton and Sarah-Jane Clarke are leaving the label they founded, Sass & Bide.

The Sydney-based designers have quit their namesake label after almost two decades.

Myer bought 65 per cent of the brand for $42.5 million in 2011, and took full ownership last September.

Since then, Clarke and Middleton reduced their roles in the company and worked as creative directors.

“Myer wishes Heidi and Sarah-Jane well, they go with our great good wishes, and we expect they will be associated with Sass & Bide for a long time,” the company said in a statement on Friday.

New design director Anthony Cuthbertson will lead the creative team with art director Bonnie O’Hare.

Cuthbertson has worked with international brands including Ralph Lauren, Daks, MaxMara and Joseph.

O’Hare has worked for Tommy Hilfiger based in Amsterdam and campaigns for Calibre, Hugo Boss and Bardot.

Comment is being sought from Sass & Bide.

AAP